The present invention relates to a softener composition.
Most of the commercially available merchandise as a softener composition for fibers are compositions comprising a quaternary ammonium salt containing two long-chain alkyl groups in one molecule and being typified by a di(long-chain alkyl) dimethyl ammonium chloride.
However, the quaternary ammonium salt described above suffers from the problem that, when residues thereof after a treatment is discharged into the environment such as a river, most of them are accumulated without biodegradation.
As an improved product against the above-mentioned problem, N-methyl-N,N-bis(long-chain alkanoyloxyethyl)-N-(2-hydroxyethyl) ammonium methyl sulfate, N,N-dimethyl-N,N-bis(alkanoyloxyethyl) ammonium chloride or the like is commercially available. Although the biodegradability of these products is improved as compared with that of the quaternary ammonium salt described above, the improved products cannot be said to be a basis for sufficiently satisfying a softening effect.
Accordingly, the object of the present invention is to provide a softener composition exhibiting an excellent softening effect and a high biodegradability and preventing a creaky feeling (or creaky feeling).
The present inventors have found that a quaternary ammonium salt having at least two long-chain alkyl groups is combined with a specific amino compound or a salt thereof, whereby the problem described above can be solved. Then, they have completed the present invention.
That is, the present invention provides a softener composition comprising the following components (A) and (B):
(A) at least one quaternary ammonium salt having at least two C5-C36 alkyl or alkenyl groups which may be interrupted by an ester linkage, amide linkage or ether linkage, and
(B) a tertiary amino compound represented by the following formula (I), a salt thereof or a mixture of the same: 
wherein R1 and R2 are the same or different and each of R1 and R2 represents a C1-C3 alkyl, hydroxyalkyl or aminoalkyl group or xe2x80x94(AO)nH, in which A represents an ethylene or propylene group and n is a number selected from 1 to 10, and R3 represents a C5-C36 alkyl or alkenyl group which is interrupted by an ester linkage, amide linkage or ether linkage (or into which an ester-, amide- or ether-bonding group is inserted).
In the component (A), the amount of the quaternary ammonium salt having at least three C5-C36 alkyl or alkenyl groups which may be interrupted by an ester linkage, amide linkage or ether linkage is preferably at least 25% by weight and more preferably at least 50% by weight.
Then, it is preferable that the quaternary ammonium salt having at least three alkyl or alkenyl groups in the component (A) is preferably one having three alkyl or alkenyl groups.
The ratio of the component (A) to the component (B) by weight is preferably from {fraction (1/9)} to {fraction (9/1)}.
The component (A) is preferably a quaternary ammonium salt having at least one ester linkage.
Further, it is preferable that the total content of the components (A) and (B) is 3 to 50% by weight and a liquid carrier is further contained therein.
The component (A) in the present invention is preferably represented by the following formula (II) or (III) or a mixture thereof: 
wherein R6 represents a C1-C3 alkyl or hydroxyalkyl group, R7 represents a C6-C36 alkyl or alkenyl group or xe2x80x94CmH2mxe2x80x94Xxe2x80x94R8, m is an integer of 1 to 6, X is xe2x80x94OCOxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94NHCOxe2x80x94, xe2x80x94CONHxe2x80x94 or xe2x80x94Oxe2x80x94, R8 represents a C5-C35 alkyl or alkenyl group, Zxe2x88x92 represents an anion, provided that the two groups selected from R6""s and R7""s may be the same or different.
The ratio of (II)/(III) is preferable {fraction (3/1)} to {fraction (0/1)} and more preferably {fraction (1/1)} to {fraction (0/1)}.
Among them, it has more preferably at least one ester group and is further preferably represented by the following formulae (IIa) and (IIIa) or (IIb) and (IIIb): 
wherein R9 represents a methyl or hydroxyethyl group, R10 represents a C5-C21 alkyl or alkenyl group, and Z1xe2x88x92 represents a chloride ion (Clxe2x88x92) or methyl sulfate ion; 
wherein each of R9, R10 and Z1xe2x88x92 has the same meaning as defined above and r is 2 or 3.
For example, the compounds represented by the formula (IIa) and (IIIa) or (IIb) and (IIIb) are synthesized by acylation of an amino alcohol such as triethanolamine, N-methyldiethanolamine, N-methyl-N-(2-hydroxyethyl)propanediamine and N,N-di(2-hydroxyethyl)propanediamine with a fatty acid or a lower alkyl ester thereof and further quaternarization of the resultant product with a quaternarizing agent such as methyl chloride (or chloromethane) and dimethyl sulfate. The degree of acylation in total is preferably 1.1 to 3.0 and more preferably 1.5 to 3.0. The fatty acid or the lower alkyl ester thereof for use is preferably a fatty acid from a coconut, a tallow fatty acid, a hardened (or hydrogenated) tallow fatty acid, stearic acid from a palm, hardened stearic acid from a palm or a lower alkyl ester thereof is particularly preferable. Further, a fat and/or oil such as a coconut oil, a tallow, a hardened tallow, a palm-stearin and a hardened palm-stearin may be used. Although the obtainable product contains compound having one, two, or three or more members selected from long-chain alkyl and alkenyl groups, depending on the amino alcohol for use, it is more than enough that the obtainable product is used as it is.
In the component (B) in the present invention, each of R1, R2 and R3 in the amino compound represented by the formula (I) has the above-defined meaning, but it is preferable that each of R1 and R2 represents a C1-C3 alkyl or hydroxyalkyl group. R3 is preferably a C7-C22 alkyl or alkenyl group which is interrupted by an ester linkage, amide linkage or ether linkage and more preferably the group which is interrupted by an ester linkage or amide linkage. It is particularly preferably an alkanoyl or alkenoyloxyethyl group, an alkanoyl or alkenoylaminoethyl group, or an alkanoyl or alkenoyl aminopropyl group.
The salt of the amino compound can be synthesized in a usual manner by neutralization with an inorganic or organic acid such as hydrochloric acid (an aqueous solution of hydrogen chloride), sulfuric acid, acetic acid, glycolic acid and citric acid.
In the composition of the present invention, the blending ratio of the component (A) to the component (B) by weight is preferably from {fraction (1/9)} to {fraction (9/1)} and, from the standpoint of an excellent softening performance, more preferably {fraction (3/7)} to {fraction (7/3)}.
The components (A) and (B) can be formed into the liquid softener composition by dispersing them in a total amount of 3 to 50% by weight in a liquid carrier such as water. In this case, the components (A) and (B) may be beforehand mixed and then introduced into water or they may be introduced one after another into water. Alternatively, the respective components maybe separately dispersed in water and then mixed.
A dispersion with water of the softener composition of the present invention has preferably pH 2 to 5 in view of a dispersibility and storage stability of the amino compound.
A higher alcohol or higher fatty acid can be added in order to further improve a softening performance. A lower alcohol such as ethanol and isopropanol, glycol or polyol as well as ethylene oxide or propylene oxide adduct can be added as a storage stabilizer. Furthermore, a usual nonionic surfactant, an inorganic salt, a pH adjuster, a hydrotropic agent, a perfume, a defoaming agent, a pigment and the like can be added if necessary.